SIOUX FALLS - A guard at the South Dakota State Penitentiary is recovering after authorities say he was assaulted by an inmate.

Corrections officials say Zane Mathis was punched several times in the head and suffered facial cuts and a broken jaw. He was taken to a Sioux Falls hospital after the attack Saturday night.

Authorities say inmate Carlos Green was subdued by other prison staff and locked up in a disciplinary section of the prison. The section of the prison where the incident happened was placed on lockdown status the rest of the night but returned to normal operations Sunday.

Green is serving more than 40 years for Brown County convictions that include aggravated assault.